[RFC PATCH bpf-next 3/3] selftests/bpf: build each test runner instance in its own sub-make

[Mykola Lysenko <nickolay.lysenko@gmail.com>]

Replace the DEFINE_TEST_RUNNER/DEFINE_TEST_RUNNER_RULES double-expansion
machinery with Makefile.runner: one sub-make invocation per test runner
instance (test_progs, test_progs-no_alu32, test_progs-cpuv4,
test_progs-bpf_gcc, test_maps), each in its own single-flavor namespace
written in plain make - no $$-escaping, no per-flavor eval guards, no
accumulating vpath directives.

The main Makefile keeps everything that exists once - tool sub-builds,
vmlinux.h, signing keys, tests.h generation, shared helper objects,
standalone binaries and the kselftest lib.mk contract - and delegates to
the runner through explicit per-instance rules. Light-skeleton demand
lists are derived from the tests' own '#include "*.lskel.h"' lines; the
bench object list is derived from $(wildcard benchs/bench_*.c). The ~20
inline $(if $(PERMISSIVE),...) fragments collapse into one skip_on_fail
helper in Makefile.buildvars.

This also fixes a latent parallel-build race (objects including libbpf
internal headers now order against the bpftool sub-build that installs
them) and makes the signing key generation rule properly grouped (the
two-target form ran genkey twice concurrently under -j).

Validation is as for the whole series: BPF objects, skeleton headers,
userspace objects and 21/22 binaries byte-identical with the previous
Makefile (bench differs only in object link order); emit_tests and the
installed tree identical; BPF CI green on x86_64 gcc/llvm, aarch64 and
s390x including GCC-BPF, ASAN and veristat jobs; all 76 benchmarks
produce identical outcomes.

Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Assisted-by: Claude:claude-fable-5 shellcheck
Signed-off-by: Mykola Lysenko <nickolay.lysenko@gmail.com>
---
 tools/testing/selftests/bpf/Makefile          | 730 ++++++------------
 .../testing/selftests/bpf/Makefile.buildvars  |   8 +
 tools/testing/selftests/bpf/Makefile.runner   | 313 ++++++++
 3 files changed, 572 insertions(+), 479 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/Makefile.runner

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index f5c0f81f6..a3ab525f7 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -1,27 +1,44 @@
 # SPDX-License-Identifier: GPL-2.0
+#
+# BPF selftests build.
+#
+# The build is split in two layers:
+#
+#   Makefile (this file)
+#       Everything that exists once: knobs and toolchain setup, libbpf /
+#       bpftool / resolve_btfids sub-builds, vmlinux.h, signing keys,
+#       generated tests.h headers, shared helper objects, standalone test
+#       binaries (bench, veristat, test_verifier, xsk*, ...), kernel test
+#       modules, docs, and the kselftest lib.mk run/install/clean
+#       contract.
+#
+#   Makefile.runner
+#       One test-runner instance (test_progs, test_progs-<flavor>,
+#       test_maps): BPF objects, skeleton headers, test objects and the
+#       final runner binary. Invoked from here once per instance; each
+#       invocation is an independent single-flavor namespace, so the
+#       runner is plain make without $$-escaping or eval.
+#
+#   gen_bpf_skel.sh
+#       Links BPF objects via bpftool and generates (light) skeletons;
+#       one script instead of four near-identical make recipes.
+#
+# Shared definitions (paths, flags, permissive-mode helpers) live in
+# Makefile.buildvars, included by both layers.
+
 include ../../../build/Build.include
 include ../../../scripts/Makefile.arch
 include ../../../scripts/Makefile.include
 
-
 # These probes gate the flavor list, which must be final before lib.mk is
 # included; keep values consistent with Makefile.buildvars.
 ifeq ($(origin BPF_GCC),undefined)
 BPF_GCC := $(shell command -v bpf-gcc;)
 endif
-
-
-
-# Some utility functions use LLVM libraries
-jit_disasm_helpers.c-CFLAGS = $(LLVM_CFLAGS)
-
-
-# Check whether bpf cpu=v4 is supported or not by clang
 ifneq ($(shell $(CLANG) --target=bpf -mcpu=help 2>&1 | grep 'v4'),)
 CLANG_CPUV4 := 1
 endif
 
-
 # Order correspond to 'make run_tests' order
 TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_progs \
 	test_sockmap \
@@ -33,16 +50,6 @@ TEST_INST_SUBDIRS := no_alu32
 ifneq ($(BPF_GCC),)
 TEST_GEN_PROGS += test_progs-bpf_gcc
 TEST_INST_SUBDIRS += bpf_gcc
-
-# The following tests contain C code that, although technically legal,
-# triggers GCC warnings that cannot be disabled: declaration of
-# anonymous struct types in function parameter lists.
-progs/btf_dump_test_case_bitfields.c-bpf_gcc-CFLAGS := -Wno-error
-progs/btf_dump_test_case_namespacing.c-bpf_gcc-CFLAGS := -Wno-error
-progs/btf_dump_test_case_packing.c-bpf_gcc-CFLAGS := -Wno-error
-progs/btf_dump_test_case_padding.c-bpf_gcc-CFLAGS := -Wno-error
-progs/btf_dump_test_case_syntax.c-bpf_gcc-CFLAGS := -Wno-error
-
 endif
 
 ifneq ($(CLANG_CPUV4),)
@@ -63,9 +70,6 @@ TEST_PROGS := test_kmod.sh \
 TEST_PROGS_EXTENDED := \
 	ima_setup.sh verify_sig_setup.sh
 
-TEST_KMODS ?= bpf_testmod.ko bpf_test_no_cfi.ko bpf_test_modorder_x.ko \
-	bpf_test_modorder_y.ko bpf_test_rqspinlock.ko
-
 # Compile but not part of 'make run_tests'
 TEST_GEN_PROGS_EXTENDED = \
 	bench \
@@ -78,8 +82,10 @@ TEST_GEN_PROGS_EXTENDED = \
 	xdp_synproxy \
 	xskxceiver
 
-TEST_GEN_FILES += $(TEST_KMODS) liburandom_read.so urandom_read sign-file uprobe_multi
+TEST_KMODS ?= bpf_testmod.ko bpf_test_no_cfi.ko bpf_test_modorder_x.ko \
+	bpf_test_modorder_y.ko bpf_test_rqspinlock.ko
 
+TEST_GEN_FILES += $(TEST_KMODS) liburandom_read.so urandom_read sign-file uprobe_multi
 
 # override lib.mk's default rules
 OVERRIDE_TARGETS := 1
@@ -98,7 +104,7 @@ endef
 include ../lib.mk
 
 NON_CHECK_FEAT_TARGETS := clean docs-clean emit_tests
-CHECK_FEAT := $(filter-out $(NON_CHECK_FEAT_TARGETS),$(or $(MAKECMDGOALS), "none"))
+CHECK_FEAT := $(filter-out $(NON_CHECK_FEAT_TARGETS),$(or $(MAKECMDGOALS),all))
 ifneq ($(CHECK_FEAT),)
 FEATURE_USER := .selftests
 FEATURE_TESTS := llvm
@@ -142,12 +148,11 @@ ifeq ($(feature-llvm),1)
 endif
 endif
 
-
 # Define simple and short `make test_progs`, `make test_maps`, etc targets
 # to build individual tests.
 # NOTE: Semicolon at the end is critical to override lib.mk's default static
 # rule for binaries.
-$(notdir $(TEST_GEN_PROGS) $(TEST_KMODS)				\
+$(notdir $(TEST_GEN_PROGS) $(TEST_KMOD_TARGETS)				\
 	 $(TEST_GEN_PROGS_EXTENDED)): %: $(OUTPUT)/% ;
 
 # sort removes libbpf duplicates when not cross-building
@@ -161,11 +166,14 @@ $(MAKE_DIRS):
 
 $(OUTPUT)/%.o: %.c
 	$(call msg,CC,,$@)
-	$(Q)$(CC) $(CFLAGS) -c $(filter %.c,$^) $(LDLIBS) -o $@
+	$(Q)$(CC) $(CFLAGS) -c $(filter %.c,$^) -o $@
 
+# Headers may appear among the prerequisites for dependency tracking;
+# they must not reach the clang/gcc command line (clang treats a bare .h
+# argument as a precompiled-header job and refuses -o).
 $(OUTPUT)/%:%.c
 	$(call msg,BINARY,,$@)
-	$(Q)$(LINK.c) $^ $(LDLIBS) -o $@
+	$(Q)$(LINK.c) $(filter-out %.h,$^) $(LDLIBS) -o $@
 
 # LLVM's ld.lld doesn't support all the architectures, so use it only on x86
 ifeq ($(SRCARCH),$(filter $(SRCARCH),x86 riscv))
@@ -202,6 +210,13 @@ $(OUTPUT)/sign-file: ../../../../scripts/sign-file.c
 		  $< -o $@ \
 		  $(shell $(PKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)
 
+# Linking uprobe_multi can fail due to relocation overflows on mips.
+$(OUTPUT)/uprobe_multi: CFLAGS += $(if $(filter mips, $(ARCH)),-mxgot)
+$(OUTPUT)/uprobe_multi: uprobe_multi.c uprobe_multi.ld
+	$(call msg,BINARY,,$@)
+	$(Q)$(CC) $(CFLAGS) -Wl,-T,uprobe_multi.ld -O0 $(LDFLAGS) 	\
+		$(filter-out %.ld,$^) $(LDLIBS) -o $@
+
 # This should really be a grouped target, but make versions before 4.3 don't
 # support that for regular rules. However, pattern matching rules are implicitly
 # treated as grouped even with older versions of make, so as a workaround, the
@@ -218,29 +233,17 @@ $(TEST_KMOD_TARGETS): $(addprefix test_kmods/,$(TEST_KMODS))
 	$(call msg,MOD,,$@)
 	$(Q)$(if $(PERMISSIVE),if [ -f test_kmods/$(@F) ]; then )cp test_kmods/$(@F) $@$(if $(PERMISSIVE),; fi)
 
-
-
 TEST_GEN_PROGS_EXTENDED += $(TRUNNER_BPFTOOL)
 
 $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED): $(BPFOBJ)
 
-TESTING_HELPERS	:= $(OUTPUT)/testing_helpers.o
-CGROUP_HELPERS	:= $(OUTPUT)/cgroup_helpers.o
-UNPRIV_HELPERS  := $(OUTPUT)/unpriv_helpers.o
-TRACE_HELPERS	:= $(OUTPUT)/trace_helpers.o
-JSON_WRITER		:= $(OUTPUT)/json_writer.o
-CAP_HELPERS	:= $(OUTPUT)/cap_helpers.o
-NETWORK_HELPERS := $(OUTPUT)/network_helpers.o
-
-$(OUTPUT)/test_sockmap: $(CGROUP_HELPERS) $(TESTING_HELPERS)
-$(OUTPUT)/test_tcpnotify_user: $(CGROUP_HELPERS) $(TESTING_HELPERS) $(TRACE_HELPERS)
-$(OUTPUT)/test_sock_fields: $(CGROUP_HELPERS) $(TESTING_HELPERS)
-$(OUTPUT)/test_tag: $(TESTING_HELPERS)
-$(OUTPUT)/test_lirc_mode2_user: $(TESTING_HELPERS)
-$(OUTPUT)/flow_dissector_load: $(TESTING_HELPERS)
-$(OUTPUT)/test_maps: $(TESTING_HELPERS)
-$(OUTPUT)/test_verifier: $(TESTING_HELPERS) $(CAP_HELPERS) $(UNPRIV_HELPERS)
-$(OUTPUT)/xsk.o: $(BPFOBJ)
+# ---------------------------------------------------------------------
+# Tool sub-builds: bpftool and libbpf (host and, when cross-compiling,
+# target variants) and resolve_btfids.
+#
+# Note the deliberate asymmetry: the host libbpf builds without
+# sanitizers and with the host toolchain.
+# ---------------------------------------------------------------------
 
 $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile)    \
 		    $(HOST_BPFOBJ) | $(HOST_BUILD_DIR)/bpftool
@@ -272,20 +275,6 @@ $(CROSS_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile)	\
 		    prefix= DESTDIR=$(SCRATCH_DIR)/ install-bin
 endif
 
-ifneq ($(SKIP_DOCS),1)
-all: docs
-endif
-
-docs:
-	$(Q)RST2MAN_OPTS="--exit-status=1" $(MAKE) $(submake_extras)	\
-	            -f Makefile.docs					\
-	            prefix= OUTPUT=$(OUTPUT)/ DESTDIR=$(OUTPUT)/ $@
-
-docs-clean:
-	$(Q)$(MAKE) $(submake_extras)					\
-	            -f Makefile.docs					\
-	            prefix= OUTPUT=$(OUTPUT)/ DESTDIR=$(OUTPUT)/ $@
-
 $(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile)		       \
 	   $(APIDIR)/linux/bpf.h					       \
 	   | $(BUILD_DIR)/libbpf
@@ -307,19 +296,6 @@ $(HOST_BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile)		       \
 		    DESTDIR=$(HOST_SCRATCH_DIR)/ prefix= all install_headers
 endif
 
-# vmlinux.h is first dumped to a temporary file and then compared to
-# the previous version. This helps to avoid unnecessary re-builds of
-# $(TRUNNER_BPF_OBJS)
-$(INCLUDE_DIR)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL) | $(INCLUDE_DIR)
-ifeq ($(VMLINUX_H),)
-	$(call msg,GEN,,$@)
-	$(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $(INCLUDE_DIR)/.vmlinux.h.tmp
-	$(Q)cmp -s $(INCLUDE_DIR)/.vmlinux.h.tmp $@ || mv $(INCLUDE_DIR)/.vmlinux.h.tmp $@
-else
-	$(call msg,CP,,$@)
-	$(Q)cp "$(VMLINUX_H)" $@
-endif
-
 $(RESOLVE_BTFIDS): $(HOST_BPFOBJ) | $(HOST_BUILD_DIR)/resolve_btfids	\
 		       $(TOOLSDIR)/bpf/resolve_btfids/main.c	\
 		       $(TOOLSDIR)/lib/rbtree.c			\
@@ -334,288 +310,38 @@ $(RESOLVE_BTFIDS): $(HOST_BPFOBJ) | $(HOST_BUILD_DIR)/resolve_btfids	\
 		HOSTPKG_CONFIG='$(PKG_CONFIG)' \
 		OUTPUT=$(HOST_BUILD_DIR)/resolve_btfids/ BPFOBJ=$(HOST_BPFOBJ)
 
-
-$(OUTPUT)/test_l4lb_noinline.o: BPF_CFLAGS += -fno-inline
-$(OUTPUT)/test_xdp_noinline.o: BPF_CFLAGS += -fno-inline
-
-$(OUTPUT)/flow_dissector_load.o: flow_dissector_load.h
-$(OUTPUT)/cgroup_getset_retval_hooks.o: cgroup_getset_retval_hooks.h
-
-# Build BPF object using Clang
-# $1 - input .c file
-# $2 - output .o file
-# $3 - CFLAGS
-# $4 - binary name
-define CLANG_BPF_BUILD_RULE
-	$(call msg,CLNG-BPF,$4,$2)
-	$(Q)$(CLANG) $3 -O2 $(BPF_TARGET_ENDIAN) -c $1 -mcpu=v3 -o $2 $(if $(PERMISSIVE),|| \
-		($(RM) $2; printf '  %-12s %s\n' 'SKIP-BPF' '$(notdir $2)' 1>&2))
-endef
-# Similar to CLANG_BPF_BUILD_RULE, but with disabled alu32
-define CLANG_NOALU32_BPF_BUILD_RULE
-	$(call msg,CLNG-BPF,$4,$2)
-	$(Q)$(CLANG) $3 -O2 $(BPF_TARGET_ENDIAN) -c $1 -mcpu=v2 -o $2 $(if $(PERMISSIVE),|| \
-		($(RM) $2; printf '  %-12s %s\n' 'SKIP-BPF' '$(notdir $2)' 1>&2))
-endef
-# Similar to CLANG_BPF_BUILD_RULE, but with cpu-v4
-define CLANG_CPUV4_BPF_BUILD_RULE
-	$(call msg,CLNG-BPF,$4,$2)
-	$(Q)$(CLANG) $3 -O2 $(BPF_TARGET_ENDIAN) -c $1 -mcpu=v4 -o $2 $(if $(PERMISSIVE),|| \
-		($(RM) $2; printf '  %-12s %s\n' 'SKIP-BPF' '$(notdir $2)' 1>&2))
-endef
-# Build BPF object using GCC
-define GCC_BPF_BUILD_RULE
-	$(call msg,GCC-BPF,$4,$2)
-	$(Q)$(BPF_GCC) $3 -DBPF_NO_PRESERVE_ACCESS_INDEX -Wno-attributes -O2 -c $1 -o $2 $(if $(PERMISSIVE),|| \
-		($(RM) $2; printf '  %-12s %s\n' 'SKIP-BPF' '$(notdir $2)' 1>&2))
-endef
-
-SKEL_BLACKLIST := btf__% test_pinning_invalid.c test_sk_assign.c
-
-LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h		\
-		linked_vars.skel.h linked_maps.skel.h 			\
-		test_subskeleton.skel.h test_subskeleton_lib.skel.h	\
-		test_usdt.skel.h tracing_multi.skel.h			\
-		tracing_multi_module.skel.h				\
-		tracing_multi_intersect.skel.h				\
-		tracing_multi_session.skel.h
-
-LSKELS := fexit_sleep.c trace_printk.c trace_vprintk.c map_ptr_kern.c 	\
-	core_kern.c core_kern_overflow.c test_ringbuf.c			\
-	test_ringbuf_n.c test_ringbuf_map_key.c test_ringbuf_write.c    \
-	test_ringbuf_overwrite.c
-
-LSKELS_SIGNED := fentry_test.c fexit_test.c atomics.c
-
-# Generate both light skeleton and libbpf skeleton for these
-LSKELS_EXTRA := test_ksyms_module.c test_ksyms_weak.c kfunc_call_test.c \
-	kfunc_call_test_subprog.c
-SKEL_BLACKLIST += $$(LSKELS) $$(LSKELS_SIGNED)
-
-test_static_linked.skel.h-deps := test_static_linked1.bpf.o test_static_linked2.bpf.o
-linked_funcs.skel.h-deps := linked_funcs1.bpf.o linked_funcs2.bpf.o
-linked_vars.skel.h-deps := linked_vars1.bpf.o linked_vars2.bpf.o
-linked_maps.skel.h-deps := linked_maps1.bpf.o linked_maps2.bpf.o
-# In the subskeleton case, we want the test_subskeleton_lib.subskel.h file
-# but that's created as a side-effect of the skel.h generation.
-test_subskeleton.skel.h-deps := test_subskeleton_lib2.bpf.o test_subskeleton_lib.bpf.o test_subskeleton.bpf.o
-test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.bpf.o test_subskeleton_lib.bpf.o
-test_usdt.skel.h-deps := test_usdt.bpf.o test_usdt_multispec.bpf.o
-xsk_xdp_progs.skel.h-deps := xsk_xdp_progs.bpf.o
-xdp_hw_metadata.skel.h-deps := xdp_hw_metadata.bpf.o
-xdp_features.skel.h-deps := xdp_features.bpf.o
-tracing_multi.skel.h-deps := tracing_multi_attach.bpf.o tracing_multi_check.bpf.o
-tracing_multi_module.skel.h-deps := tracing_multi_attach_module.bpf.o tracing_multi_check.bpf.o
-tracing_multi_intersect.skel.h-deps := tracing_multi_intersect_attach.bpf.o tracing_multi_check.bpf.o
-tracing_multi_session.skel.h-deps := tracing_multi_session_attach.bpf.o tracing_multi_check.bpf.o
-
-LINKED_BPF_OBJS := $(foreach skel,$(LINKED_SKELS),$($(skel)-deps))
-LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.c,$(LINKED_BPF_OBJS))
-
-HEADERS_FOR_BPF_OBJS := $(wildcard $(BPFDIR)/*.bpf.h)		\
-			$(wildcard $(CURDIR)/libarena/include/*.[ch])	\
-			$(addprefix $(BPFDIR)/,	bpf_core_read.h	\
-			                        bpf_endian.h	\
-						bpf_helpers.h	\
-			                        bpf_tracing.h)
-
-# Set up extra TRUNNER_XXX "temporary" variables in the environment (relies on
-# $eval()) and pass control to DEFINE_TEST_RUNNER_RULES.
-# Parameters:
-# $1 - test runner base binary name (e.g., test_progs)
-# $2 - test runner extra "flavor" (e.g., no_alu32, cpuv4, bpf_gcc, etc)
-define DEFINE_TEST_RUNNER
-
-LSKEL_SIGN := -S -k $(PRIVATE_KEY) -i $(VERIFICATION_CERT)
-TRUNNER_OUTPUT := $(OUTPUT)$(if $2,/)$2
-TRUNNER_BINARY := $1$(if $2,-)$2
-TRUNNER_TEST_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.test.o,	\
-				 $$(notdir $$(wildcard $(TRUNNER_TESTS_DIR)/*.c)))
-TRUNNER_EXTRA_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.o,		\
-				 $$(filter %.c,$(TRUNNER_EXTRA_SOURCES)))
-TRUNNER_LIB_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.o,		\
-				 $$(filter %.c,$(TRUNNER_LIB_SOURCES)))
-TRUNNER_EXTRA_HDRS := $$(filter %.h,$(TRUNNER_EXTRA_SOURCES))
-TRUNNER_TESTS_HDR := $(TRUNNER_TESTS_DIR)/tests.h
-TRUNNER_BPF_SRCS := $$(notdir $$(wildcard $(TRUNNER_BPF_PROGS_DIR)/*.c))
-TRUNNER_BPF_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.bpf.o, $$(TRUNNER_BPF_SRCS))
-TRUNNER_BPF_SKELS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.skel.h,	\
-				 $$(filter-out $(SKEL_BLACKLIST) $(LINKED_BPF_SRCS),\
-					       $$(TRUNNER_BPF_SRCS)))
-TRUNNER_BPF_LSKELS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.lskel.h, $$(LSKELS) $$(LSKELS_EXTRA))
-TRUNNER_BPF_SKELS_LINKED := $$(addprefix $$(TRUNNER_OUTPUT)/,$(LINKED_SKELS))
-TRUNNER_BPF_LSKELS_SIGNED := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.lskel.h, $$(LSKELS_SIGNED))
-TEST_GEN_FILES += $$(TRUNNER_BPF_OBJS)
-
-# Evaluate rules now with extra TRUNNER_XXX variables above already defined
-$$(eval $$(call DEFINE_TEST_RUNNER_RULES,$1,$2))
-
-endef
-
-# Using TRUNNER_XXX variables, provided by callers of DEFINE_TEST_RUNNER and
-# set up by DEFINE_TEST_RUNNER itself, create test runner build rules with:
-# $1 - test runner base binary name (e.g., test_progs)
-# $2 - test runner extra "flavor" (e.g., no_alu32, cpuv4, bpf_gcc, etc)
-define DEFINE_TEST_RUNNER_RULES
-
-# Permissive build behaviour (skip-on-failure compile, partial-link) only
-# applies to test_progs and its flavors; runners that use strong cross-object
-# references (e.g. test_maps) keep strict semantics even when permissive.
-# The check is inlined per-runner so $1 is substituted at $(call) time and
-# the result is baked into each rule's recipe.
-
-ifeq ($($(TRUNNER_OUTPUT)-dir),)
-$(TRUNNER_OUTPUT)-dir := y
-$(TRUNNER_OUTPUT):
-	$$(call msg,MKDIR,,$$@)
-	$(Q)mkdir -p $$@
-endif
-
-# ensure we set up BPF objects generation rule just once for a given
-# input/output directory combination
-ifeq ($($(TRUNNER_BPF_PROGS_DIR)$(if $2,-)$2-bpfobjs),)
-$(TRUNNER_BPF_PROGS_DIR)$(if $2,-)$2-bpfobjs := y
-$(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.bpf.o:				\
-		     $(TRUNNER_BPF_PROGS_DIR)/%.c			\
-		     $(TRUNNER_BPF_PROGS_DIR)/*.h			\
-		     $$(INCLUDE_DIR)/vmlinux.h				\
-		     $(HEADERS_FOR_BPF_OBJS)				\
-		     | $(TRUNNER_OUTPUT) $$(BPFOBJ)
-	$$(call $(TRUNNER_BPF_BUILD_RULE),$$<,$$@,			\
-					  $(TRUNNER_BPF_CFLAGS)         \
-					  $$($$<-CFLAGS)		\
-					  $$($$<-$2-CFLAGS),$(TRUNNER_BINARY))
-
-$(TRUNNER_BPF_SKELS): %.skel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
-	$(Q)BPFTOOL=$$(BPFTOOL) ./gen_bpf_skel.sh --tag '$(TRUNNER_BINARY)'	\
-		--name $$(notdir $$(<:.bpf.o=)) --infix linked			\
-		--skel $$@ --subskel $$(@:.skel.h=.subskel.h) $$< $(if $(PERMISSIVE),|| { \
-		$$(RM) $$@ $$(@:.skel.h=.subskel.h);				\
-		printf '  %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; })
-
-$(TRUNNER_BPF_LSKELS): %.lskel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
-	$(Q)BPFTOOL=$$(BPFTOOL) ./gen_bpf_skel.sh --tag '$(TRUNNER_BINARY)'	\
-		--name $$(notdir $$(<:.bpf.o=_lskel)) --infix llinked --lskel	\
-		--skel $$@ $$< $(if $(PERMISSIVE),|| {				\
-		$$(RM) $$@;							\
-		printf '  %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; })
-
-$(TRUNNER_BPF_LSKELS_SIGNED): %.lskel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
-	$(Q)BPFTOOL=$$(BPFTOOL) ./gen_bpf_skel.sh --tag '$(TRUNNER_BINARY) (signed)' \
-		--name $$(notdir $$(<:.bpf.o=_lskel)) --infix llinked		\
-		--sign '$(LSKEL_SIGN)'						\
-		--skel $$@ $$< $(if $(PERMISSIVE),|| {				\
-		$$(RM) $$@;							\
-		printf '  %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; })
-
-$(LINKED_BPF_OBJS): %: $(TRUNNER_OUTPUT)/%
-
-# .SECONDEXPANSION here allows to correctly expand %-deps variables as prerequisites
-.SECONDEXPANSION:
-$(TRUNNER_BPF_SKELS_LINKED): $(TRUNNER_OUTPUT)/%: $$$$(%-deps) $(BPFTOOL) | $(TRUNNER_OUTPUT)
-	$(Q)BPFTOOL=$$(BPFTOOL) ./gen_bpf_skel.sh --tag '$(TRUNNER_BINARY)'	\
-		--name $$(notdir $$(@:.skel.h=)) --infix linked			\
-		--skel $$@ --subskel $$(@:.skel.h=.subskel.h)			\
-		$$(addprefix $(TRUNNER_OUTPUT)/,$$($$(@F)-deps)) $(if $(PERMISSIVE),|| { \
-		$$(RM) $$@ $$(@:.skel.h=.subskel.h);				\
-		printf '  %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; })
-
-# When the compiler generates a %.d file, only skel basenames (not
-# full paths) are specified as prerequisites for corresponding %.o
-# file. vpath directives below instruct make to search for skel files
-# in TRUNNER_OUTPUT, if they are not present in the working directory.
-vpath %.skel.h $(TRUNNER_OUTPUT)
-vpath %.lskel.h $(TRUNNER_OUTPUT)
-vpath %.subskel.h $(TRUNNER_OUTPUT)
-
+ifneq ($(SKIP_DOCS),1)
+all: docs
 endif
 
-# ensure we set up tests.h header generation rule just once
-ifeq ($($(TRUNNER_TESTS_DIR)-tests-hdr),)
-$(TRUNNER_TESTS_DIR)-tests-hdr := y
-$(TRUNNER_TESTS_HDR): $(TRUNNER_TESTS_DIR)/*.c
-	$$(call msg,TEST-HDR,$(TRUNNER_BINARY),$$@)
-	$$(shell (echo '/* Generated header, do not edit */';					\
-		  sed -n -E 's/^void (serial_)?test_([a-zA-Z0-9_]+)\((void)?\).*/DEFINE_TEST(\2)/p'	\
-			$(TRUNNER_TESTS_DIR)/*.c | sort ;	\
-		 ) > $$@)
-endif
+docs:
+	$(Q)RST2MAN_OPTS="--exit-status=1" $(MAKE) $(submake_extras)	\
+	            -f Makefile.docs					\
+	            prefix= OUTPUT=$(OUTPUT)/ DESTDIR=$(OUTPUT)/ $@
 
-$(TRUNNER_OUTPUT)/resolve_btfids.test.o: $(RESOLVE_BTFIDS) $(TRUNNER_OUTPUT)/btf_data.bpf.o
-$(TRUNNER_OUTPUT)/resolve_btfids.test.o: private TEST_NEEDS_BTFIDS = 1
-
-# compile individual test files
-# Note: we cd into output directory to ensure embedded BPF object is found
-$(TRUNNER_TEST_OBJS): $(TRUNNER_OUTPUT)/%.test.o:			\
-		      $(TRUNNER_TESTS_DIR)/%.c				\
-		      | $(TRUNNER_OUTPUT)/%.test.d
-	$$(call msg,TEST-OBJ,$(TRUNNER_BINARY),$$@)
-	$(Q)(cd $$(@D) && $$(CC) -I. $$(CFLAGS) -MMD -MT $$@ -c $(CURDIR)/$$< $$(LDLIBS) -o $$(@F)) $(if $(filter test_progs%,$1),$(if $(PERMISSIVE),|| \
-		($(RM) $$@; printf '  %-12s %s\n' 'SKIP-TEST' '$$(notdir $$@)' 1>&2)))
-	$$(if $$(TEST_NEEDS_BTFIDS),						\
-		$(Q)if [ -f $$@ ]; then						\
-		$(if $(filter 1,$(V)),true,printf '  %-8s%s %s\n' "BTFIDS" " [$(TRUNNER_BINARY)]" "$$(notdir $$@)"); \
-		$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.bpf.o $$@;	\
-		$(RESOLVE_BTFIDS) --patch_btfids $$@.BTF_ids $$@;		\
-		fi)
-
-$(TRUNNER_TEST_OBJS:.o=.d): $(TRUNNER_OUTPUT)/%.test.d:			\
-			    $(TRUNNER_TESTS_DIR)/%.c			\
-			    $(TRUNNER_EXTRA_HDRS)			\
-			    $$(BPFOBJ) | $(TRUNNER_OUTPUT)		\
-			    $(TRUNNER_BPF_SKELS)			\
-			    $(TRUNNER_BPF_LSKELS)			\
-			    $(TRUNNER_BPF_LSKELS_SIGNED)		\
-			    $(TRUNNER_BPF_SKELS_LINKED)
-
-ifeq ($(filter clean docs-clean emit_tests,$(MAKECMDGOALS)),)
-include $(wildcard $(TRUNNER_TEST_OBJS:.o=.d))
-endif
+docs-clean:
+	$(Q)$(MAKE) $(submake_extras)					\
+	            -f Makefile.docs					\
+	            prefix= OUTPUT=$(OUTPUT)/ DESTDIR=$(OUTPUT)/ $@
 
-# add per extra obj CFGLAGS definitions
-$(foreach N,$(patsubst $(TRUNNER_OUTPUT)/%.o,%,$(TRUNNER_EXTRA_OBJS)),	\
-	$(eval $(TRUNNER_OUTPUT)/$(N).o: CFLAGS += $($(N).c-CFLAGS)))
-
-$(TRUNNER_EXTRA_OBJS): $(TRUNNER_OUTPUT)/%.o:				\
-		       %.c						\
-		       $(TRUNNER_EXTRA_HDRS)				\
-		       $(VERIFY_SIG_HDR)				\
-		       $(TRUNNER_TESTS_HDR)				\
-		       $$(BPFOBJ) | $(TRUNNER_OUTPUT)
-	$$(call msg,EXT-OBJ,$(TRUNNER_BINARY),$$@)
-	$(Q)$$(CC) $$(CFLAGS) -c $$< $$(LDLIBS) -o $$@
-
-$(TRUNNER_LIB_OBJS): $(TRUNNER_OUTPUT)/%.o:$(TOOLSDIR)/lib/%.c
-	$$(call msg,LIB-OBJ,$(TRUNNER_BINARY),$$@)
-	$(Q)$$(CC) $$(CFLAGS) -c $$< $$(LDLIBS) -o $$@
-
-# non-flavored in-srctree builds receive special treatment, in particular, we
-# do not need to copy extra resources (see e.g. test_btf_dump_case())
-$(TRUNNER_BINARY)-extras: $(TRUNNER_EXTRA_FILES) | $(TRUNNER_OUTPUT)
-ifneq ($2:$(OUTPUT),:$(shell pwd))
-	$$(call msg,EXT-COPY,$(TRUNNER_BINARY),$(TRUNNER_EXTRA_FILES))
-	$(Q)rsync -aq $(if $(PERMISSIVE),--ignore-missing-args) $$^ $(TRUNNER_OUTPUT)/
+# vmlinux.h is first dumped to a temporary file and then compared to
+# the previous version. This helps to avoid unnecessary re-builds of
+# BPF objects.
+$(INCLUDE_DIR)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL) | $(INCLUDE_DIR)
+ifeq ($(VMLINUX_H),)
+	$(call msg,GEN,,$@)
+	$(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $(INCLUDE_DIR)/.vmlinux.h.tmp
+	$(Q)cmp -s $(INCLUDE_DIR)/.vmlinux.h.tmp $@ || mv $(INCLUDE_DIR)/.vmlinux.h.tmp $@
+else
+	$(call msg,CP,,$@)
+	$(Q)cp "$(VMLINUX_H)" $@
 endif
 
-# some X.test.o files have runtime dependencies on Y.bpf.o files
-$(OUTPUT)/$(TRUNNER_BINARY): | $(TRUNNER_BPF_OBJS)
-
-$(OUTPUT)/$(TRUNNER_BINARY): $(if $(filter test_progs%,$1),$(if $(PERMISSIVE),$$(wildcard $(TRUNNER_TEST_OBJS)),$(TRUNNER_TEST_OBJS)),$(TRUNNER_TEST_OBJS))	\
-			     $(TRUNNER_EXTRA_OBJS) $$(BPFOBJ)		\
-			     $(TRUNNER_LIB_OBJS)			\
-			     $(TRUNNER_BPFTOOL)				\
-			     $(OUTPUT)/veristat				\
-			     | $(TRUNNER_BINARY)-extras			\
-			     $(if $(filter test_progs%,$1),$(if $(PERMISSIVE),$(TRUNNER_TEST_OBJS)))
-	$$(call msg,BINARY,,$$@)
-	$(Q)$$(CC) $$(CFLAGS) $(if $(filter test_progs%,$1),$(if $(PERMISSIVE),$$(filter %.a %.o,$$(wildcard $(TRUNNER_TEST_OBJS)) $$(filter-out $(TRUNNER_TEST_OBJS),$$^)),$$(filter %.a %.o,$$^)),$$(filter %.a %.o,$$^)) $$(LDLIBS) $$(LLVM_LDLIBS) $$(LDFLAGS) $$(LLVM_LDFLAGS) -o $$@
-	$(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/$(USE_BOOTSTRAP)bpftool \
-		   $(OUTPUT)/$(if $2,$2/)bpftool
-
-endef
-
-
-$(VERIFICATION_CERT) $(PRIVATE_KEY): $(VERIFY_SIG_SETUP)
+# One genkey run produces both files. A plain two-target rule is not
+# grouped - under -j make would run genkey twice concurrently and the
+# openssl invocations race; the pattern form is implicitly grouped even
+# with make < 4.3 (same workaround as the test_kmods rule).
+$(BUILD_DIR)/%.pem $(BUILD_DIR)/%.der: $(VERIFY_SIG_SETUP)
 	$(Q)mkdir -p $(BUILD_DIR)
 	$(Q)$(VERIFY_SIG_SETUP) genkey $(BUILD_DIR)
 
@@ -644,113 +370,183 @@ LIBARENA_BPF_DEPS := $(wildcard libarena/Makefile		\
 				 libarena/selftests/*		\
 				 libarena/*.bpf.o)
 
-
 $(LIBARENA_SKEL): $(INCLUDE_DIR)/vmlinux.h $(BPFOBJ) $(LIBARENA_BPF_DEPS)
 	+$(MAKE) -C libarena libarena.skel.h $(LIBARENA_MAKE_ARGS)
 
-ifneq ($(CLANG_HAS_ARENA_ASAN),)
+libarena: $(LIBARENA_SKEL)
 
+ifneq ($(CLANG_HAS_ARENA_ASAN),)
 $(LIBARENA_ASAN_SKEL): $(INCLUDE_DIR)/vmlinux.h $(BPFOBJ) $(LIBARENA_BPF_DEPS)
 	+$(MAKE) -C libarena libarena_asan.skel.h $(LIBARENA_MAKE_ARGS)
+
+libarena_asan: $(LIBARENA_ASAN_SKEL)
 endif
 
-# Define test_progs test runner.
-TRUNNER_TESTS_DIR := prog_tests
-TRUNNER_BPF_PROGS_DIR := progs
-TRUNNER_EXTRA_SOURCES := test_progs.c		\
-			 cgroup_helpers.c	\
-			 trace_helpers.c	\
-			 network_helpers.c	\
-			 testing_helpers.c	\
-			 btf_helpers.c		\
-			 cap_helpers.c		\
-			 unpriv_helpers.c 	\
-			 sysctl_helpers.c	\
-			 netlink_helpers.c	\
-			 jit_disasm_helpers.c	\
-			 io_helpers.c		\
-			 test_loader.c		\
-			 xsk.c			\
-			 disasm.c		\
-			 disasm_helpers.c	\
-			 json_writer.c 		\
-			 $(VERIFY_SIG_HDR)		\
-			 flow_dissector_load.h	\
-			 ip_check_defrag_frags.h	\
-			 bpftool_helpers.c	\
-			 usdt_1.c usdt_2.c	\
-			 $(LIBARENA_SKEL)	\
-			 $(LIBARENA_ASAN_SKEL)
-TRUNNER_LIB_SOURCES := find_bit.c
-TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read				\
-		       $(OUTPUT)/liburandom_read.so			\
-		       $(OUTPUT)/xdp_synproxy				\
-		       $(OUTPUT)/sign-file				\
-		       $(OUTPUT)/uprobe_multi				\
-		       $(TEST_KMOD_TARGETS)				\
-		       ima_setup.sh 					\
-		       $(VERIFY_SIG_SETUP)				\
-		       $(wildcard progs/btf_dump_test_case_*.c)		\
-		       $(wildcard progs/*.bpf.o)
-TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE
-TRUNNER_BPF_CFLAGS := $(BPF_CFLAGS) $(CLANG_CFLAGS) -DENABLE_ATOMICS_TESTS
-$(eval $(call DEFINE_TEST_RUNNER,test_progs))
-
-# Define test_progs-no_alu32 test runner.
-TRUNNER_BPF_BUILD_RULE := CLANG_NOALU32_BPF_BUILD_RULE
-TRUNNER_BPF_CFLAGS := $(BPF_CFLAGS) $(CLANG_CFLAGS)
-$(eval $(call DEFINE_TEST_RUNNER,test_progs,no_alu32))
-
-# Define test_progs-cpuv4 test runner.
+# ---------------------------------------------------------------------
+# Generated test list headers
+# ---------------------------------------------------------------------
+
+define gen_tests_hdr
+	$(call msg,TEST-HDR,,$@)
+	$(Q)(echo '/* Generated header, do not edit */';		\
+	     sed -n -E 's/^void (serial_)?test_([a-zA-Z0-9_]+)\((void)?\).*/DEFINE_TEST(\2)/p' \
+		$(@D)/*.c | sort) > $@
+endef
+
+prog_tests/tests.h: $(wildcard prog_tests/*.c)
+	$(gen_tests_hdr)
+
+map_tests/tests.h: $(wildcard map_tests/*.c)
+	$(gen_tests_hdr)
+
+verifier/tests.h: verifier/*.c
+	$(Q)( cd verifier/; \
+	      echo '/* Generated header, do not edit */'; \
+	      echo '#ifdef FILL_ARRAY'; \
+	      ls *.c 2> /dev/null | sed -e 's@\(.*\)@#include \"\1\"@'; \
+	      echo '#endif' \
+	    ) > verifier/tests.h
+
+# ---------------------------------------------------------------------
+# Shared helper objects, used by the standalone binaries below and (as
+# prebuilt inputs) by the unflavored test_progs runner.
+# ---------------------------------------------------------------------
+
+# Some utility functions use LLVM libraries
+$(OUTPUT)/jit_disasm_helpers.o: CFLAGS += $(LLVM_CFLAGS)
+
+HELPER_OBJS := $(addprefix $(OUTPUT)/,testing_helpers.o cgroup_helpers.o \
+	       trace_helpers.o network_helpers.o json_writer.o		\
+	       cap_helpers.o unpriv_helpers.o usdt_1.o usdt_2.o xsk.o)
+
+# $(BPFTOOL) is a prerequisite because its sub-make is what installs
+# libbpf's internal headers (bpf/hashmap.h, bpf/libbpf_internal.h) into
+# $(INCLUDE_DIR); without it, helpers including those headers race the
+# install and can silently pick up the source-tree copies instead.
+$(HELPER_OBJS): flow_dissector_load.h ip_check_defrag_frags.h		\
+		$(VERIFY_SIG_HDR) prog_tests/tests.h $(BPFOBJ) $(BPFTOOL)
+
+$(OUTPUT)/test_sockmap: $(OUTPUT)/cgroup_helpers.o $(OUTPUT)/testing_helpers.o
+$(OUTPUT)/test_tcpnotify_user: $(OUTPUT)/cgroup_helpers.o		\
+			       $(OUTPUT)/testing_helpers.o		\
+			       $(OUTPUT)/trace_helpers.o
+$(OUTPUT)/test_tag: $(OUTPUT)/testing_helpers.o
+$(OUTPUT)/test_lirc_mode2_user: $(OUTPUT)/testing_helpers.o
+$(OUTPUT)/flow_dissector_load: flow_dissector_load.h $(OUTPUT)/testing_helpers.o
+
+# ---------------------------------------------------------------------
+# Test runner instances, one sub-make each (see Makefile.runner).
+# ---------------------------------------------------------------------
+
+# The LLVM feature-probe results are exported to the runner sub-makes.
+# CC is passed explicitly instead: exporting it would also leak lib.mk's
+# CC into the libbpf/bpftool/resolve_btfids sub-builds, which compute
+# their own.
+export LLVM_CFLAGS LLVM_LDLIBS LLVM_LDFLAGS
+
+RUNNER_MAKE := $(MAKE) -f Makefile.runner OUTPUT=$(OUTPUT) CC='$(CC)'
+
+# Everything a runner instance references but does not know how to build.
+RUNNER_PREREQS := $(INCLUDE_DIR)/vmlinux.h $(BPFOBJ) $(BPFTOOL)		\
+		  $(TRUNNER_BPFTOOL) $(RESOLVE_BTFIDS)			\
+		  $(OUTPUT)/veristat					\
+		  $(VERIFY_SIG_HDR) $(PRIVATE_KEY) $(VERIFICATION_CERT)	\
+		  $(LIBARENA_SKEL) $(LIBARENA_ASAN_SKEL)		\
+		  prog_tests/tests.h					\
+		  $(HELPER_OBJS)					\
+		  $(OUTPUT)/urandom_read $(OUTPUT)/liburandom_read.so	\
+		  $(OUTPUT)/xdp_synproxy $(OUTPUT)/sign-file		\
+		  $(OUTPUT)/uprobe_multi $(TEST_KMOD_TARGETS)
+
+FORCE:
+
+# The default flavor's skeletons are also inputs of bench, test_maps,
+# xskxceiver, xdp_* and test_cpp; "default-skels" builds just those
+# without the test_progs test objects and binary.
+.PHONY: default-skels
+default-skels: $(RUNNER_PREREQS)
+	+$(Q)$(RUNNER_MAKE) RUNNER=test_progs FLAVOR= TESTS_DIR=prog_tests \
+		BPF_BUILD=clang BPF_MCPU=v3 BPF_DEFINES=-DENABLE_ATOMICS_TESTS skels
+
+$(OUTPUT)/test_progs: $(RUNNER_PREREQS) default-skels FORCE
+	+$(Q)$(RUNNER_MAKE) RUNNER=test_progs FLAVOR= TESTS_DIR=prog_tests \
+		BPF_BUILD=clang BPF_MCPU=v3 BPF_DEFINES=-DENABLE_ATOMICS_TESTS
+
+$(OUTPUT)/test_progs-no_alu32: $(RUNNER_PREREQS) FORCE
+	+$(Q)$(RUNNER_MAKE) RUNNER=test_progs FLAVOR=no_alu32 TESTS_DIR=prog_tests \
+		BPF_BUILD=clang BPF_MCPU=v2
+
 ifneq ($(CLANG_CPUV4),)
-TRUNNER_BPF_BUILD_RULE := CLANG_CPUV4_BPF_BUILD_RULE
-TRUNNER_BPF_CFLAGS := $(BPF_CFLAGS) $(CLANG_CFLAGS) -DENABLE_ATOMICS_TESTS
-$(eval $(call DEFINE_TEST_RUNNER,test_progs,cpuv4))
+$(OUTPUT)/test_progs-cpuv4: $(RUNNER_PREREQS) FORCE
+	+$(Q)$(RUNNER_MAKE) RUNNER=test_progs FLAVOR=cpuv4 TESTS_DIR=prog_tests \
+		BPF_BUILD=clang BPF_MCPU=v4 BPF_DEFINES=-DENABLE_ATOMICS_TESTS
 endif
 
-# Define test_progs BPF-GCC-flavored test runner.
 ifneq ($(BPF_GCC),)
-TRUNNER_BPF_BUILD_RULE := GCC_BPF_BUILD_RULE
-TRUNNER_BPF_CFLAGS := $(BPF_CFLAGS) $(call get_sys_includes,gcc,)
-$(eval $(call DEFINE_TEST_RUNNER,test_progs,bpf_gcc))
+$(OUTPUT)/test_progs-bpf_gcc: $(RUNNER_PREREQS) FORCE
+	+$(Q)$(RUNNER_MAKE) RUNNER=test_progs FLAVOR=bpf_gcc TESTS_DIR=prog_tests \
+		BPF_BUILD=gcc
 endif
 
-# Define test_maps test runner.
-TRUNNER_TESTS_DIR := map_tests
-TRUNNER_BPF_PROGS_DIR := progs
-TRUNNER_EXTRA_SOURCES := test_maps.c
-TRUNNER_LIB_SOURCES :=
-TRUNNER_EXTRA_FILES :=
-TRUNNER_BPF_BUILD_RULE := $$(error no BPF objects should be built)
-TRUNNER_BPF_CFLAGS :=
-$(eval $(call DEFINE_TEST_RUNNER,test_maps))
-
-# Define test_verifier test runner.
-# It is much simpler than test_maps/test_progs and sufficiently different from
-# them (e.g., test.h is using completely pattern), that it's worth just
-# explicitly defining all the rules explicitly.
-verifier/tests.h: verifier/*.c
-	$(shell ( cd verifier/; \
-		  echo '/* Generated header, do not edit */'; \
-		  echo '#ifdef FILL_ARRAY'; \
-		  ls *.c 2> /dev/null | sed -e 's@\(.*\)@#include \"\1\"@'; \
-		  echo '#endif' \
-		) > verifier/tests.h)
-$(OUTPUT)/test_verifier: test_verifier.c verifier/tests.h $(BPFOBJ) | $(OUTPUT)
+# test_maps compiles map_tests/*.c against the default flavor's skeletons
+$(OUTPUT)/test_maps: $(RUNNER_PREREQS) map_tests/tests.h default-skels FORCE
+	+$(Q)$(RUNNER_MAKE) RUNNER=test_maps FLAVOR= TESTS_DIR=map_tests \
+		BPF_BUILD=none
+
+# Default-flavor BPF objects and skeletons consumed by targets in this
+# Makefile (and by lib.mk's install rule) are produced by the runner
+# sub-make above; the empty recipe plus the order-only prerequisite
+# makes them available here without duplicating the runner's rules.
+DEFAULT_BPF_OBJS := $(patsubst progs/%.c,$(OUTPUT)/%.bpf.o,$(wildcard progs/*.c))
+TEST_GEN_FILES += $(DEFAULT_BPF_OBJS)
+
+BENCH_SKELS := $(addprefix $(OUTPUT)/,					\
+	       test_overhead.skel.h trigger_bench.skel.h		\
+	       ringbuf_bench.skel.h perfbuf_bench.skel.h		\
+	       bloom_filter_bench.skel.h bpf_loop_bench.skel.h		\
+	       strncmp_bench.skel.h bpf_hashmap_full_update_bench.skel.h\
+	       local_storage_bench.skel.h				\
+	       local_storage_rcu_tasks_trace_bench.skel.h		\
+	       bench_local_storage_create.skel.h			\
+	       bpf_hashmap_lookup.skel.h htab_mem_bench.skel.h		\
+	       crypto_bench.skel.h bench_sockmap_prog.skel.h		\
+	       lpm_trie_bench.skel.h lpm_trie_map.skel.h		\
+	       bpf_nop_bench.skel.h xdp_lb_bench.skel.h)
+TOP_SKELS := $(addprefix $(OUTPUT)/,xsk_xdp_progs.skel.h		\
+	     xdp_hw_metadata.skel.h xdp_features.skel.h			\
+	     test_core_extern.skel.h) $(BENCH_SKELS)
+
+# Empty-recipe delegation: "default-skels" (re)builds the file via the
+# runner sub-make, after which make re-stats the target, so dependents
+# see fresh timestamps within the same invocation. Dependents still
+# rebuild on mtime only - the phony prerequisite does not cascade.
+$(DEFAULT_BPF_OBJS) $(TOP_SKELS): default-skels ;
+
+# ---------------------------------------------------------------------
+# Standalone test binaries
+# ---------------------------------------------------------------------
+
+# test_verifier is much simpler than test_maps/test_progs and
+# sufficiently different from them (e.g., its tests.h uses a completely
+# different pattern), that it's worth just defining its rules explicitly.
+$(OUTPUT)/test_verifier: test_verifier.c verifier/tests.h $(BPFOBJ)	\
+			 $(OUTPUT)/testing_helpers.o			\
+			 $(OUTPUT)/cap_helpers.o			\
+			 $(OUTPUT)/unpriv_helpers.o
 	$(call msg,BINARY,,$@)
 	$(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@
 
 # Include find_bit.c to compile xskxceiver.
 EXTRA_SRC := $(TOOLSDIR)/lib/find_bit.c prog_tests/test_xsk.c prog_tests/test_xsk.h
-$(OUTPUT)/xskxceiver: $(EXTRA_SRC) xskxceiver.c xskxceiver.h $(OUTPUT)/network_helpers.o $(OUTPUT)/xsk.o $(OUTPUT)/xsk_xdp_progs.skel.h $(BPFOBJ) | $(OUTPUT)
+$(OUTPUT)/xskxceiver: $(EXTRA_SRC) xskxceiver.c xskxceiver.h $(OUTPUT)/network_helpers.o $(OUTPUT)/xsk.o $(OUTPUT)/xsk_xdp_progs.skel.h $(BPFOBJ)
 	$(call msg,BINARY,,$@)
 	$(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@
 
-$(OUTPUT)/xdp_hw_metadata: xdp_hw_metadata.c $(OUTPUT)/network_helpers.o $(OUTPUT)/xsk.o $(OUTPUT)/xdp_hw_metadata.skel.h | $(OUTPUT)
+$(OUTPUT)/xdp_hw_metadata: xdp_hw_metadata.c $(OUTPUT)/network_helpers.o $(OUTPUT)/xsk.o $(OUTPUT)/xdp_hw_metadata.skel.h
 	$(call msg,BINARY,,$@)
 	$(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@
 
-$(OUTPUT)/xdp_features: xdp_features.c $(OUTPUT)/network_helpers.o $(OUTPUT)/xdp_features.skel.h | $(OUTPUT)
+$(OUTPUT)/xdp_features: xdp_features.c $(OUTPUT)/network_helpers.o $(OUTPUT)/xdp_features.skel.h
 	$(call msg,BINARY,,$@)
 	$(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@
 
@@ -762,11 +558,18 @@ $(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ)
 	$(call msg,CXX,,$@)
 	$(Q)$(CXX) $(CXXFLAGS) $(filter %.a %.o %.cpp,$^) $(LDLIBS) -o $@
 
-# Benchmark runner
-$(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h $(BPFOBJ)
+# ---------------------------------------------------------------------
+# Benchmark runner. The benchmark list is defined by the files in
+# benchs/: every benchs/bench_*.c is compiled and linked in.
+# ---------------------------------------------------------------------
+
+BENCH_OBJS := $(sort $(patsubst benchs/%.c,$(OUTPUT)/%.o,$(wildcard benchs/bench_*.c)))
+
+$(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h $(BPFOBJ) | default-skels
 	$(call msg,CC,,$@)
-	$(Q)$(CC) $(CFLAGS) -O2 -c $(filter %.c,$^) $(LDLIBS) -o $@ $(if $(PERMISSIVE),|| \
-		($(RM) $@; printf '  %-12s %s\n' 'SKIP-BENCH' '$(notdir $@)' 1>&2))
+	$(Q)$(CC) $(CFLAGS) -O2 -c $(filter %.c,$^) -o $@ $(call skip_on_fail,BENCH)
+
+# benchmark-specific generated-skeleton dependencies
 $(OUTPUT)/bench_rename.o: $(OUTPUT)/test_overhead.skel.h
 $(OUTPUT)/bench_trigger.o: $(OUTPUT)/trigger_bench.skel.h
 $(OUTPUT)/bench_ringbufs.o: $(OUTPUT)/ringbuf_bench.skel.h \
@@ -786,37 +589,19 @@ $(OUTPUT)/bench_lpm_trie_map.o: $(OUTPUT)/lpm_trie_bench.skel.h $(OUTPUT)/lpm_tr
 $(OUTPUT)/bench_bpf_nop.o: $(OUTPUT)/bpf_nop_bench.skel.h bench_bpf_timing.h
 $(OUTPUT)/bench_xdp_lb.o: $(OUTPUT)/xdp_lb_bench.skel.h bench_bpf_timing.h
 $(OUTPUT)/bench_bpf_timing.o: bench_bpf_timing.h
+
 $(OUTPUT)/bench.o: bench.h testing_helpers.h $(BPFOBJ)
 $(OUTPUT)/bench: LDLIBS += -lm
-$(OUTPUT)/bench: $(OUTPUT)/bench.o \
-		 $(TESTING_HELPERS) \
-		 $(TRACE_HELPERS) \
-		 $(CGROUP_HELPERS) \
-		 $(OUTPUT)/bench_count.o \
-		 $(OUTPUT)/bench_rename.o \
-		 $(OUTPUT)/bench_trigger.o \
-		 $(OUTPUT)/bench_ringbufs.o \
-		 $(OUTPUT)/bench_bloom_filter_map.o \
-		 $(OUTPUT)/bench_bpf_loop.o \
-		 $(OUTPUT)/bench_strncmp.o \
-		 $(OUTPUT)/bench_bpf_hashmap_full_update.o \
-		 $(OUTPUT)/bench_local_storage.o \
-		 $(OUTPUT)/bench_local_storage_rcu_tasks_trace.o \
-		 $(OUTPUT)/bench_bpf_hashmap_lookup.o \
-		 $(OUTPUT)/bench_local_storage_create.o \
-		 $(OUTPUT)/bench_htab_mem.o \
-		 $(OUTPUT)/bench_bpf_crypto.o \
-		 $(OUTPUT)/bench_sockmap.o \
-		 $(OUTPUT)/bench_lpm_trie_map.o \
-		 $(OUTPUT)/bench_bpf_timing.o \
-		 $(OUTPUT)/bench_bpf_nop.o \
-		 $(OUTPUT)/bench_xdp_lb.o \
-		 $(OUTPUT)/usdt_1.o \
-		 $(OUTPUT)/usdt_2.o \
-		 #
+$(OUTPUT)/bench: $(OUTPUT)/bench.o		\
+		 $(OUTPUT)/testing_helpers.o	\
+		 $(OUTPUT)/trace_helpers.o	\
+		 $(OUTPUT)/cgroup_helpers.o	\
+		 $(OUTPUT)/usdt_1.o		\
+		 $(OUTPUT)/usdt_2.o		\
+		 $(BENCH_OBJS)
 	$(call msg,BINARY,,$@)
-	$(Q)$(CC) $(CFLAGS) $(LDFLAGS) $(filter %.a %.o,$^) $(LDLIBS) -o $@ $(if $(PERMISSIVE),|| \
-		($(RM) $@; printf '  %-12s %s\n' 'SKIP-LINK' '$(notdir $@) (some benchmarks may have been skipped)' 1>&2))
+	$(Q)$(CC) $(CFLAGS) $(LDFLAGS) $(filter %.a %.o,$^) $(LDLIBS) -o $@ \
+		$(call skip_on_fail,LINK,,(some benchmarks may have been skipped))
 
 # This works around GCC warning about snprintf truncating strings like:
 #
@@ -828,13 +613,6 @@ $(OUTPUT)/veristat: $(OUTPUT)/veristat.o
 	$(call msg,BINARY,,$@)
 	$(Q)$(CC) $(CFLAGS) $(LDFLAGS) $(filter %.a %.o,$^) $(LDLIBS) -o $@
 
-# Linking uprobe_multi can fail due to relocation overflows on mips.
-$(OUTPUT)/uprobe_multi: CFLAGS += $(if $(filter mips, $(ARCH)),-mxgot)
-$(OUTPUT)/uprobe_multi: uprobe_multi.c uprobe_multi.ld
-	$(call msg,BINARY,,$@)
-	$(Q)$(CC) $(CFLAGS) -Wl,-T,uprobe_multi.ld -O0 $(LDFLAGS) 	\
-		$(filter-out %.ld,$^) $(LDLIBS) -o $@
-
 EXTRA_CLEAN := $(SCRATCH_DIR) $(HOST_SCRATCH_DIR)			\
 	prog_tests/tests.h map_tests/tests.h verifier/tests.h		\
 	feature bpftool $(TEST_KMOD_TARGETS)				\
@@ -844,7 +622,7 @@ EXTRA_CLEAN := $(SCRATCH_DIR) $(HOST_SCRATCH_DIR)			\
 			       liburandom_read.so)			\
 	$(OUTPUT)/FEATURE-DUMP.selftests
 
-.PHONY: docs docs-clean
+.PHONY: docs docs-clean libarena libarena_asan
 
 # Delete partially updated (corrupted) files on error
 .DELETE_ON_ERROR:
@@ -868,9 +646,3 @@ override define INSTALL_RULE
 			$(INSTALL_PATH)/$$DIR;				  \
 	done
 endef
-
-libarena: $(LIBARENA_SKEL)
-
-ifneq ($(CLANG_HAS_ARENA_ASAN),)
-libarena_asan: $(LIBARENA_ASAN_SKEL)
-endif
diff --git a/tools/testing/selftests/bpf/Makefile.buildvars b/tools/testing/selftests/bpf/Makefile.buildvars
index 2a7efe6d1..ea975feef 100644
--- a/tools/testing/selftests/bpf/Makefile.buildvars
+++ b/tools/testing/selftests/bpf/Makefile.buildvars
@@ -62,6 +62,14 @@ SKIP_CRYPTO	?=
 BPF_STRICT_BUILD ?= 1
 PERMISSIVE := $(filter 0,$(BPF_STRICT_BUILD))
 
+# Permissive-mode recipe suffix: on failure, remove the target, emit a
+# SKIP marker and report success so the rest of the build continues.
+# $(1) - SKIP tag (BPF, TEST, BENCH, SKEL, LINK, ...)
+# $(2) - optional extra files to remove alongside the target
+# $(3) - optional note appended to the SKIP message
+skip_on_fail = $(if $(PERMISSIVE),|| { $(RM) $@ $(2); \
+	printf '  %-12s %s\n' 'SKIP-$(1)' '$(notdir $@)$(if $(3), $(3))' 1>&2; })
+
 # Kernel test modules; TEST_KMODS= on the command line disables them.
 TEST_KMODS ?= bpf_testmod.ko bpf_test_no_cfi.ko bpf_test_modorder_x.ko \
 	bpf_test_modorder_y.ko bpf_test_rqspinlock.ko
diff --git a/tools/testing/selftests/bpf/Makefile.runner b/tools/testing/selftests/bpf/Makefile.runner
new file mode 100644
index 000000000..4c58cc51f
--- /dev/null
+++ b/tools/testing/selftests/bpf/Makefile.runner
@@ -0,0 +1,313 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Build one BPF test-runner instance: test_progs, one of its flavors
+# (no_alu32, cpuv4, bpf_gcc), or test_maps.
+#
+# Each instance is an independent sub-make with its own output directory,
+# so everything here is written in plain make - no $$-escaping, no eval,
+# no per-flavor guards. This file is always invoked by the main Makefile,
+# never directly: all shared prerequisites (libbpf, bpftool, vmlinux.h,
+# veristat, helper objects, signing key, generated tests.h, extra
+# binaries) are built by the main Makefile *before* this one runs and are
+# referenced below as plain files.
+#
+# Parameters (all passed on the sub-make command line):
+#   OUTPUT      absolute path of the selftests output directory
+#   RUNNER      base binary name: test_progs | test_maps
+#   FLAVOR      flavor suffix: empty | no_alu32 | cpuv4 | bpf_gcc
+#   TESTS_DIR   directory with the test sources: prog_tests | map_tests
+#   BPF_BUILD   how to build progs/*.c BPF objects: clang | gcc | none
+#   BPF_MCPU    clang -mcpu= value: v2 | v3 | v4
+#   BPF_DEFINES extra defines for BPF objects (e.g. -DENABLE_ATOMICS_TESTS)
+#   CC          C compiler (as resolved by lib.mk in the main Makefile)
+#   LLVM_CFLAGS/LLVM_LDLIBS/LLVM_LDFLAGS
+#               results of the top-level LLVM feature probe
+
+include ../../../build/Build.include
+include ../../../scripts/Makefile.arch
+include ../../../scripts/Makefile.include
+
+# Same message helpers as ../lib.mk, which only the top level includes.
+ifeq ($(V),1)
+Q =
+msg =
+else
+Q = @
+msg = @printf '  %-8s%s %s%s\n' "$(1)" "$(if $(2), [$(2)])" "$(notdir $(3))" "$(if $(4), $(4))";
+MAKEFLAGS += --no-print-directory
+endif
+
+include Makefile.buildvars
+
+# Keep in sync with the CFLAGS/LDFLAGS additions in ../lib.mk.
+CFLAGS += -D_GNU_SOURCE=
+CFLAGS += -I$(srctree)/tools/testing/selftests
+CFLAGS += $(USERCFLAGS)
+LDFLAGS += $(USERLDFLAGS)
+ifneq ($(LLVM),)
+CFLAGS += -Wno-address-of-packed-member
+CFLAGS += -Wno-gnu-variable-sized-type-not-at-end
+endif
+
+BINARY := $(RUNNER)$(if $(FLAVOR),-$(FLAVOR))
+RDIR   := $(OUTPUT)$(if $(FLAVOR),/$(FLAVOR))
+
+all: $(OUTPUT)/$(BINARY)
+.PHONY: all
+
+# Delete partially updated (corrupted) files on error
+.DELETE_ON_ERROR:
+
+# Permissive skip-on-failure of individual tests applies to test_progs and
+# its flavors only; test_maps uses strong cross-object references and keeps
+# strict semantics even when BPF_STRICT_BUILD=0.
+PERMISSIVE_TESTS := $(if $(filter test_progs,$(RUNNER)),$(PERMISSIVE))
+
+$(RDIR):
+	$(call msg,MKDIR,,$@)
+	$(Q)mkdir -p $@
+
+# ---------------------------------------------------------------------
+# Per-runner sources
+# ---------------------------------------------------------------------
+
+ifeq ($(RUNNER),test_progs)
+EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c		\
+		 network_helpers.c testing_helpers.c btf_helpers.c	\
+		 cap_helpers.c unpriv_helpers.c sysctl_helpers.c	\
+		 netlink_helpers.c jit_disasm_helpers.c io_helpers.c	\
+		 test_loader.c xsk.c disasm.c disasm_helpers.c		\
+		 json_writer.c bpftool_helpers.c usdt_1.c usdt_2.c
+LIB_SOURCES := find_bit.c
+EXTRA_HDRS := flow_dissector_load.h ip_check_defrag_frags.h		\
+	      $(VERIFY_SIG_HDR) $(LIBARENA_SKEL) $(LIBARENA_ASAN_SKEL)
+EXTRA_FILES := $(OUTPUT)/urandom_read $(OUTPUT)/liburandom_read.so	\
+	       $(OUTPUT)/xdp_synproxy $(OUTPUT)/sign-file		\
+	       $(OUTPUT)/uprobe_multi					\
+	       $(TEST_KMOD_TARGETS)					\
+	       ima_setup.sh $(VERIFY_SIG_SETUP)				\
+	       $(wildcard progs/btf_dump_test_case_*.c)			\
+	       $(wildcard progs/*.bpf.o)
+endif
+
+ifeq ($(RUNNER),test_maps)
+EXTRA_SOURCES := test_maps.c testing_helpers.c
+endif
+
+# Note on the unflavored runners, which share $(OUTPUT) with the main
+# Makefile: helper objects the main Makefile also uses (and lists in the
+# runner prerequisites) are already built and fresh when a runner starts,
+# so the rules below find them up to date and never write them.
+
+TESTS_HDR := $(TESTS_DIR)/tests.h
+
+TEST_SRCS  := $(notdir $(wildcard $(TESTS_DIR)/*.c))
+TEST_OBJS  := $(patsubst %.c,$(RDIR)/%.test.o,$(TEST_SRCS))
+TEST_DEPS  := $(TEST_OBJS:.o=.d)
+EXTRA_OBJS := $(patsubst %.c,$(RDIR)/%.o,$(filter %.c,$(EXTRA_SOURCES)))
+LIB_OBJS   := $(patsubst %.c,$(RDIR)/%.o,$(LIB_SOURCES))
+
+# ---------------------------------------------------------------------
+# BPF objects and skeletons
+# ---------------------------------------------------------------------
+
+ifneq ($(BPF_BUILD),none)
+
+BPF_SRCS := $(notdir $(wildcard progs/*.c))
+BPF_OBJS := $(patsubst %.c,$(RDIR)/%.bpf.o,$(BPF_SRCS))
+
+# Which tests want a light skeleton is derived from the test sources
+# themselves: an '#include "foo.lskel.h"' line is the single source of
+# truth. Tests that include both foo.skel.h and foo.lskel.h get both.
+skel_includes = $(shell grep -rhoE '"[a-zA-Z0-9_]+\.$(1)"' prog_tests benchs map_tests *.c *.cpp 2>/dev/null)
+LSKEL_BASES := $(sort $(patsubst "%.lskel.h",%,$(call skel_includes,lskel.h)))
+SKEL_DEMANDED := $(sort $(patsubst "%.skel.h",%,$(call skel_includes,skel.h)))
+
+# Signing is not expressed in the include, so the signed subset stays
+# explicit.
+LSKELS_SIGNED := fentry_test fexit_test atomics
+
+# BPF objects that cannot have a regular skeleton, plus lskel-only tests
+# (light-skeleton users whose sources never include the .skel.h form).
+SKEL_BLACKLIST := btf__% test_pinning_invalid.c test_sk_assign.c \
+		  $(addsuffix .c,$(filter-out $(SKEL_DEMANDED),$(LSKEL_BASES)))
+
+# Skeletons made by linking multiple BPF objects together. The %-deps
+# mapping is the only hand-maintained metadata: it cannot be derived from
+# the sources.
+test_static_linked.skel.h-deps := test_static_linked1.bpf.o test_static_linked2.bpf.o
+linked_funcs.skel.h-deps := linked_funcs1.bpf.o linked_funcs2.bpf.o
+linked_vars.skel.h-deps := linked_vars1.bpf.o linked_vars2.bpf.o
+linked_maps.skel.h-deps := linked_maps1.bpf.o linked_maps2.bpf.o
+# In the subskeleton case, we want the test_subskeleton_lib.subskel.h file
+# but that's created as a side-effect of the skel.h generation.
+test_subskeleton.skel.h-deps := test_subskeleton_lib2.bpf.o test_subskeleton_lib.bpf.o test_subskeleton.bpf.o
+test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.bpf.o test_subskeleton_lib.bpf.o
+test_usdt.skel.h-deps := test_usdt.bpf.o test_usdt_multispec.bpf.o
+tracing_multi.skel.h-deps := tracing_multi_attach.bpf.o tracing_multi_check.bpf.o
+tracing_multi_module.skel.h-deps := tracing_multi_attach_module.bpf.o tracing_multi_check.bpf.o
+tracing_multi_intersect.skel.h-deps := tracing_multi_intersect_attach.bpf.o tracing_multi_check.bpf.o
+tracing_multi_session.skel.h-deps := tracing_multi_session_attach.bpf.o tracing_multi_check.bpf.o
+
+LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h		\
+		linked_vars.skel.h linked_maps.skel.h			\
+		test_subskeleton.skel.h test_subskeleton_lib.skel.h	\
+		test_usdt.skel.h tracing_multi.skel.h			\
+		tracing_multi_module.skel.h				\
+		tracing_multi_intersect.skel.h				\
+		tracing_multi_session.skel.h
+LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
+
+SKELS := $(patsubst %.c,$(RDIR)/%.skel.h,				\
+	   $(filter-out $(SKEL_BLACKLIST) $(LINKED_BPF_SRCS),$(BPF_SRCS)))
+LSKELS_H        := $(patsubst %,$(RDIR)/%.lskel.h,$(filter-out $(LSKELS_SIGNED),$(LSKEL_BASES)))
+LSKELS_SIGNED_H := $(patsubst %,$(RDIR)/%.lskel.h,$(LSKELS_SIGNED))
+LINKED_SKELS_H  := $(addprefix $(RDIR)/,$(LINKED_SKELS))
+ALL_SKELS := $(SKELS) $(LSKELS_H) $(LSKELS_SIGNED_H) $(LINKED_SKELS_H)
+
+HEADERS_FOR_BPF_OBJS := $(wildcard $(BPFDIR)/*.bpf.h)			\
+			$(wildcard $(CURDIR)/libarena/include/*.[ch])	\
+			$(addprefix $(BPFDIR)/,	bpf_core_read.h		\
+						bpf_endian.h		\
+						bpf_helpers.h		\
+						bpf_tracing.h)
+
+# Per-source BPF compilation flag overrides ($<-CFLAGS / $<-$(FLAVOR)-CFLAGS).
+# GCC cannot disable "declaration of anonymous struct in parameter list"
+# warnings triggered by these (technically legal) test programs.
+progs/btf_dump_test_case_bitfields.c-bpf_gcc-CFLAGS := -Wno-error
+progs/btf_dump_test_case_namespacing.c-bpf_gcc-CFLAGS := -Wno-error
+progs/btf_dump_test_case_packing.c-bpf_gcc-CFLAGS := -Wno-error
+progs/btf_dump_test_case_padding.c-bpf_gcc-CFLAGS := -Wno-error
+progs/btf_dump_test_case_syntax.c-bpf_gcc-CFLAGS := -Wno-error
+
+ifeq ($(BPF_BUILD),gcc)
+BPF_CC_MSG := GCC-BPF
+# Note: sys includes come from the *host* gcc, not $(BPF_GCC) - bpf-gcc's
+# own search path lacks the host's asm-generic/ headers. Computed once
+# here: bpf_cc below is deferred and expands per compiled object.
+GCC_SYS_INCLUDES := $(call get_sys_includes,gcc,)
+bpf_cc = $(BPF_GCC) $(BPF_CFLAGS) $(GCC_SYS_INCLUDES)			\
+	 $(BPF_DEFINES) $($<-CFLAGS) $($<-$(FLAVOR)-CFLAGS)		\
+	 -DBPF_NO_PRESERVE_ACCESS_INDEX -Wno-attributes -O2 -c $< -o $@
+else
+BPF_CC_MSG := CLNG-BPF
+bpf_cc = $(CLANG) $(BPF_CFLAGS) $(CLANG_CFLAGS) $(BPF_DEFINES)		\
+	 $($<-CFLAGS) $($<-$(FLAVOR)-CFLAGS)				\
+	 -O2 $(BPF_TARGET_ENDIAN) -c $< -mcpu=$(BPF_MCPU) -o $@
+endif
+
+$(BPF_OBJS): $(RDIR)/%.bpf.o: progs/%.c progs/*.h			\
+	     $(INCLUDE_DIR)/vmlinux.h $(HEADERS_FOR_BPF_OBJS)		\
+	     | $(RDIR) $(BPFOBJ)
+	$(call msg,$(BPF_CC_MSG),$(BINARY),$@)
+	$(Q)$(bpf_cc) $(call skip_on_fail,BPF)
+
+# gen_bpf_skel.sh picks the bpftool binary up from the environment.
+export BPFTOOL
+GEN_SKEL := ./gen_bpf_skel.sh
+
+$(SKELS): $(RDIR)/%.skel.h: $(RDIR)/%.bpf.o $(BPFTOOL) | $(RDIR)
+	$(Q)$(GEN_SKEL) --tag '$(BINARY)' --name $* --infix linked	\
+		--skel $@ --subskel $(@:.skel.h=.subskel.h) $<		\
+		$(call skip_on_fail,SKEL,$(@:.skel.h=.subskel.h))
+
+$(LSKELS_H): $(RDIR)/%.lskel.h: $(RDIR)/%.bpf.o $(BPFTOOL) | $(RDIR)
+	$(Q)$(GEN_SKEL) --tag '$(BINARY)' --name $*_lskel --infix llinked \
+		--lskel --skel $@ $< $(call skip_on_fail,SKEL)
+
+$(LSKELS_SIGNED_H): $(RDIR)/%.lskel.h: $(RDIR)/%.bpf.o $(BPFTOOL)	\
+		    $(PRIVATE_KEY) $(VERIFICATION_CERT) | $(RDIR)
+	$(Q)$(GEN_SKEL) --tag '$(BINARY) (signed)' --name $*_lskel	\
+		--infix llinked						\
+		--sign '-S -k $(PRIVATE_KEY) -i $(VERIFICATION_CERT)'	\
+		--skel $@ $< $(call skip_on_fail,SKEL)
+
+.SECONDEXPANSION:
+$(LINKED_SKELS_H): $(RDIR)/%.skel.h: $$(addprefix $(RDIR)/,$$($$*.skel.h-deps)) \
+		   $(BPFTOOL) | $(RDIR)
+	$(Q)$(GEN_SKEL) --tag '$(BINARY)' --name $* --infix linked	\
+		--skel $@ --subskel $(@:.skel.h=.subskel.h)		\
+		$(addprefix $(RDIR)/,$($*.skel.h-deps))			\
+		$(call skip_on_fail,SKEL,$(@:.skel.h=.subskel.h))
+
+endif # BPF_BUILD != none
+
+.PHONY: skels
+skels: $(ALL_SKELS)
+
+# When the compiler generates a %.d file, only skel basenames (not full
+# paths) are specified as prerequisites for the corresponding %.o file.
+# The vpath directives instruct make to also search for skel files in
+# $(RDIR) if they are not present in the working directory.
+vpath %.skel.h $(RDIR)
+vpath %.lskel.h $(RDIR)
+vpath %.subskel.h $(RDIR)
+
+# ---------------------------------------------------------------------
+# Test objects and runner binary
+# ---------------------------------------------------------------------
+
+$(RDIR)/resolve_btfids.test.o: $(RESOLVE_BTFIDS) $(RDIR)/btf_data.bpf.o
+$(RDIR)/resolve_btfids.test.o: private TEST_NEEDS_BTFIDS = 1
+
+# Compile individual test files.
+# Note: we cd into the output directory to ensure embedded BPF objects
+# are found. The %.test.d dependency files are a side effect of the -MMD
+# below; the separate no-recipe rule for them orders the first
+# compilation after skeleton generation and re-orders test object
+# compilation when headers change.
+$(TEST_OBJS): $(RDIR)/%.test.o: $(TESTS_DIR)/%.c | $(RDIR)/%.test.d
+	$(call msg,TEST-OBJ,$(BINARY),$@)
+	$(Q)(cd $(@D) && $(CC) -I. $(CFLAGS) -MMD -MT $@ -c $(CURDIR)/$< -o $(@F)) \
+		$(if $(PERMISSIVE_TESTS),$(call skip_on_fail,TEST))
+	$(if $(TEST_NEEDS_BTFIDS),					\
+		$(Q)if [ -f $@ ]; then					\
+		$(if $(filter 1,$(V)),true,printf '  %-8s%s %s\n' "BTFIDS" " [$(BINARY)]" "$(notdir $@)"); \
+		$(RESOLVE_BTFIDS) --btf $(RDIR)/btf_data.bpf.o $@;	\
+		$(RESOLVE_BTFIDS) --patch_btfids $@.BTF_ids $@;		\
+		fi)
+
+$(TEST_DEPS): $(RDIR)/%.test.d: $(TESTS_DIR)/%.c $(EXTRA_HDRS) $(BPFOBJ) \
+	      | $(RDIR) $(ALL_SKELS)
+
+include $(wildcard $(TEST_DEPS))
+
+$(RDIR)/jit_disasm_helpers.o: CFLAGS += $(LLVM_CFLAGS)
+
+$(EXTRA_OBJS): $(RDIR)/%.o: %.c $(EXTRA_HDRS) $(TESTS_HDR) $(BPFOBJ) | $(RDIR)
+	$(call msg,EXT-OBJ,$(BINARY),$@)
+	$(Q)$(CC) $(CFLAGS) -c $< -o $@
+
+$(LIB_OBJS): $(RDIR)/%.o: $(TOOLSDIR)/lib/%.c | $(RDIR)
+	$(call msg,LIB-OBJ,$(BINARY),$@)
+	$(Q)$(CC) $(CFLAGS) -c $< -o $@
+
+# Non-flavored in-srctree builds receive special treatment, in particular
+# we do not need to copy extra resources (see e.g. test_btf_dump_case()).
+.PHONY: extras
+extras: $(if $(PERMISSIVE),$(wildcard $(EXTRA_FILES)),$(EXTRA_FILES)) | $(RDIR)
+ifneq ($(FLAVOR):$(OUTPUT),:$(CURDIR))
+ifneq ($(strip $(EXTRA_FILES)),)
+	$(call msg,EXT-COPY,$(BINARY),$(notdir $(EXTRA_FILES)))
+	$(Q)rsync -aq $(if $(PERMISSIVE),--ignore-missing-args) $(EXTRA_FILES) $(RDIR)/
+endif
+endif
+
+# In permissive mode, link whatever test objects were successfully built
+# (their compilation may have been skipped); the wildcard in the recipe
+# picks up the survivors at link time.
+# Prerequisite order is also link order (test objects, extra objects,
+# libbpf, lib objects).
+$(OUTPUT)/$(BINARY): $(if $(PERMISSIVE_TESTS),,$(TEST_OBJS))		\
+		     $(EXTRA_OBJS) $(BPFOBJ) $(LIB_OBJS)		\
+		     $(TRUNNER_BPFTOOL) $(OUTPUT)/veristat		\
+		     | extras $(BPF_OBJS)				\
+		     $(if $(PERMISSIVE_TESTS),$(TEST_OBJS))
+	$(call msg,BINARY,,$@)
+	$(Q)$(CC) $(CFLAGS)						\
+		$(if $(PERMISSIVE_TESTS),$(wildcard $(TEST_OBJS)))	\
+		$(filter %.a %.o,$^)					\
+		$(LDLIBS) $(LLVM_LDLIBS) $(LDFLAGS) $(LLVM_LDFLAGS) -o $@
+	$(Q)ln -sf $(if $(FLAVOR),..,.)/tools/build/bpftool/$(USE_BOOTSTRAP)bpftool \
+		   $(RDIR)/bpftool
-- 
2.43.0